oalib
Search Results: 1 - 10 of 100 matches for " "
All listed articles are free for downloading (OA Articles)
Page 1 /100
Display every page Item
Biocompatibility of Poly-ε-caprolactone-hydroxyapatite composite on mouse bone marrow-derived osteoblasts and endothelial cells
Haiying Yu, Paul H Wooley, Shang-You Yang
Journal of Orthopaedic Surgery and Research , 2009, DOI: 10.1186/1749-799x-4-5
Abstract: Mononuclear cells were induced to osteoblasts and endothelial cells respectively, which were defined by the expression of osteocalcin, alkaline phosphatase (ALP), and deposits of calcium-containing crystal for osteoblasts, or by the expression of vascular endothelial growth factor receptor-2 (VEGFR-2) and von Willebrand factor (vWF), and the formation of a capillary network in Matrigel? for endothelial cells. Both types of cell were seeded respectively on PCL-HA scaffolds at HA to PCL weight ratio of 1:1, 1:4, or 0:1 and were evaluated using scanning electron microscopy, ALP activity (of osteoblasts) and nitric oxide production (of endothelial cells) plus the assessment of cell viability.The results indicated that HA led to a positive stimulation of osteoblasts viability and ALP activity, while HA showed less influence on endothelial cells viability. An elevated nitric oxide production of endothelial cells was observed in HA-containing group.Supplement of HA into PCL improved biocompatible for bone marrow-derived osteoblasts and endothelial cells. The PCL-HA composite integrating with two types of cells may provide a useful system for tissue-engineered bone grafts with vascularization.One approach to tissue engineering consists of seeding appropriate cells on a biodegradable scaffold, stimulating cell growth and differentiation in vitro, and then implanting the engineered complex in vivo to achieve functional tissue [1,2]. However seeding a single cell type into a biomaterial scaffold to replace an injured tissue that consists of multiple cell types is usually inapplicable. An alternative strategy is the generation of a composite graft, which contains not only the tissue specific cell types, but also other supportive cells, such as endothelial cells (ECs) to promote vascularization of the grafts.ECs may be incorporated into bioengineered tissue[3,4]to promote the tissue revascularization, and transportation of oxygen and nutrients. Unfortunately, differentiated ECs
Repair of critical-size defects with autogenous periosteum-derived cells combined with bovine anorganic apatite/collagen: an experimental study in rat calvaria
Paulo, Anderson de Oliveira;Castro-Silva, Igor Iuco;Oliveira, Davi Ferreira de;Machado, Manoel Eduardo de Lima;Bonetti-Filho, Idomeo;Granjeiro, José Mauro;
Brazilian Dental Journal , 2011, DOI: 10.1590/S0103-64402011000400011
Abstract: the aim of this study was to evaluate the bone repair using autogenous periosteum-derived cells (pdc) and bovine anorganic apatite and collagen (ha-col). pdc from wistar rats (n=10) were seeded on ha-col discs and subjected to osteoinduction during 6 days. critical-size defects in rat calvarias were treated with blood clot (g1), autogenous bone (g2), ha-col (g3) and ha-col combined with pdc (g4) (n=40), and then analyzed 1 and 3 months after surgeries. radiographic analysis exhibited no significant temporal change. g1 and g2 had discrete new marginal bone, but the radiopacity of graft materials in g2, g3 and g4 impaired the detection of osteogenesis. at 3 months, histopathological analysis showed the presence of ossification islets in g1, which was more evident in g2, homogeneous new bone around ha-col in g3 and heterogeneous new bone around ha-col in g4 in addition to moderate presence of foreign body cells in g3 and g4. histomorphometric analysis showed no change in the volume density of xenograft (p>0.05) and bone volume density in g2 was twice greater than in g1 and g4 after 3 months (p<0.05), but similar to g3. the pdc did not increase bone formation in vivo, although the biomaterial alone showed biocompatibility and osteoconduction capacity.
Histologic Evaluation of Bone Healing Following Application of Anorganic Bovine Bone and β-tricalcium Phosphate in Rabbit Calvaria  [cached]
AR. Rokn,N. Moslemi,B. Eslami,H. Khandagh Abadi
Journal of Dentistry of Tehran University of Medical Sciences , 2012,
Abstract: Objective: Both anorganic bovine bone (ABB) and β-tricalcium phosphate (β- TCP) are used in clinical practice as bone substitute materials, but there is limited data comparing these two materials in standardized defects.The aim of this study was to histologically evaluate the effectiveness of ABB and β-TCP in the healing of experimentally induced bone defects.Materials and Methods: Eighteen bone defects were created on the calvaria of six rabbits. In each animal, one defect was left untreated and the other two werefilled with ABB and β-TCP. After one month, histological sections were prepared.Type and vitality of newly formed bone, percentage of new bone formation and residual material, thickness of trabeculae, inflammation and foreign body reaction were assessed.Results: The newly formed osseous tissue was vital in all defects and consisted of woven and lamellar bone. Mean percentages of new bone formation were 30.83±14.29%, 16.83±11.07% and 14.00±8.17% in β-TCP, ABB and control groups, respectively and the mean percentages of residual biomaterial were 24.17±14.01% and 36.50±8.43% in β-TCP and ABB groups, respectively. However,the differences were not statistically significant (all ps>0.05). Inflammatoryinfiltration was statistically higher in β-TCP compared to the control group (p=0.025), but the difference was not significant between β-TCP and ABB groups (p=0.083). Trabeculation thickness and foreign body reaction were not statistically different between β-TCP and ABB groups.Conclusion: β-TCP and ABB were not different with regard to the quantity and quality of newly formed osseous tissue. However, inflammatory infiltration washigher in sites filled with β-TCP.
Microscopic analisys of porous microgranular bovine anorganic bone implanted in rat subcutaneous tissue
Zambuzzi, Willian Fernando;Oliveira, Rodrigo Cardoso de;Alanis, Danilo;Menezes, Renato;Letra, Ariadne;Cestari, Tania Mary;Taga, Rumio;Granjeiro, José Mauro;
Journal of Applied Oral Science , 2005, DOI: 10.1590/S1678-77572005000400013
Abstract: the tissue response to porous bovine anorganic bone implanted in rat connective tissue was evaluated by subjective light microscopy analysis. forty rats were divided into two groups: control (empty collagen capsules) and test (collagen capsule filled with 0.1g biomaterial) and killed 10, 20, 30 and 60 days after implantation. at 10 days, intense chronic inflammatory infiltrate consisting mainly of macrophages and inflammatory multinucleated giant cells (imgc) was observed. neutrophils, plasma cells and lymphocytes were present in discrete amounts and slowly disappeared along the repair process. porosity of the material was filled by reaction connective tissue exhibiting imgc. the fibrosis was more intense after 60 days and clearly higher than the control group. thus, the material did not cause any severe adverse reactions and did not stimulate the immune system. based on the results it could be concluded that deproteinized bovine cancelous bone was well tolerated by rat connective tissue.
Rat subcutaneous tissue response to macrogranular porous anorganic bovine bone graft
Zambuzzi, Willian Fernando;Oliveira, Rodrigo Cardoso de;Pereira, Felipe Ladeira;Cestari, Tania Mary;Taga, Rumio;Granjeiro, José Mauro;
Brazilian Dental Journal , 2006, DOI: 10.1590/S0103-64402006000400002
Abstract: the ideal bone graft must present biocompatibility, osteoconductive and osteoinductive properties, resistance and plasticity. xenogenic grafts of bovine cancellous bone origin are particularly interesting due to their biologically designed porous structure that enhance both cellular and vascular invasion. the purpose of this study was to evaluate the tissue response induced by bovine macrogranular porous anorganic bone implanted in rat subcutaneous tissue. forty rats were assigned to 2 groups, as follows: the control group received empty collagen capsules and the test group received subcutaneous implants of the test material. samples were collected after 10, 20, 30 and 60 days and processed histologically. histological analysis showed at 10 days a granulomatous inflammatory infiltrate, rich in multinucleated giant cells and free of lymphocytes or plasma cells, similarly to mineralized allograft implanted in rat subcutaneous. in later periods, there was a significant decrease in the inflammatory infiltrate and an increase in fibrosis around graft particles. in conclusion, the test material induced a foreign body-type granuloma with subsequent fibrosis around the graft particles implanted in rat subcutaneous and did not elicit any immune response, thus being considered biocompatible.
Osteoblasts and their applications in bone tissue engineering  [cached]
Rupani A,Balint R,Cartmell SH
Cell Health and Cytoskeleton , 2012,
Abstract: Asha Rupani1, Richard Balint2, Sarah H Cartmell1,21Institute of Science and Technology in Medicine, Keele University, Hartshill, Stoke-on-Trent, UK; 2Materials Science Centre, The University of Manchester, Manchester, UKAbstract: Tissue engineering is an emerging therapy that offers a new solution to patients suffering from bone loss. It utilizes cells derived from such sources as a patient's own bone or bone marrow, which are laboratory-isolated, grown (so they multiply in number), and placed onto a degradable material, or scaffold, that has mechanical/chemical properties appropriate to the bone section that it is replacing. The cells plus the scaffold are then grown in a container, or bioreactor, which is necessary as it provides the correct environment required for the cells to proliferate, differentiate, and to produce extracellular matrix. The following review focuses on the use of osteoblasts for bone tissue engineering.Keywords: osteoblast, bone, tissue engineering, regenerative medicine, orthopaedic
Osteoblasts and their applications in bone tissue engineering
Rupani A, Balint R, Cartmell SH
Cell Health and Cytoskeleton , 2012, DOI: http://dx.doi.org/10.2147/CHC.S21845
Abstract: teoblasts and their applications in bone tissue engineering Review (2262) Total Article Views Authors: Rupani A, Balint R, Cartmell SH Published Date May 2012 Volume 2012:4 Pages 49 - 61 DOI: http://dx.doi.org/10.2147/CHC.S21845 Received: 05 March 2012 Accepted: 22 March 2012 Published: 08 May 2012 Asha Rupani1, Richard Balint2, Sarah H Cartmell1,2 1Institute of Science and Technology in Medicine, Keele University, Hartshill, Stoke-on-Trent, UK; 2Materials Science Centre, The University of Manchester, Manchester, UK Abstract: Tissue engineering is an emerging therapy that offers a new solution to patients suffering from bone loss. It utilizes cells derived from such sources as a patient's own bone or bone marrow, which are laboratory-isolated, grown (so they multiply in number), and placed onto a degradable material, or scaffold, that has mechanical/chemical properties appropriate to the bone section that it is replacing. The cells plus the scaffold are then grown in a container, or bioreactor, which is necessary as it provides the correct environment required for the cells to proliferate, differentiate, and to produce extracellular matrix. The following review focuses on the use of osteoblasts for bone tissue engineering.
Ectopic bone formation in bone marrow stem cell seeded calcium phosphate scaffolds as compared to autograft and (cell seeded) allograft  [PDF]
J O Eniwumide,H Yuan,S H Cartmell,G J Meijer
European Cells and Materials (ECM) , 2007,
Abstract: Improvements to current therapeutic strategies are needed for the treatment of skeletal defects. Bone tissue engineering offers potential advantages to these strategies. In this study, ectopic bone formation in a range of scaffolds was assessed. Vital autograft and devitalised allograft served as controls and the experimental groups comprised autologous bone marrow derived stem cell seeded allograft, biphasic calcium phosphate (BCP) and tricalcium phosphate (TCP), respectively. All implants were implanted in the back muscle of adult Dutch milk goats for 12 weeks. Micro-computed tomography (μCT) analysis and histomorphometry was performed to evaluate and quantify ectopic bone formation. In good agreement, both μCT and histomorphometric analysis demonstrated a significant increase in bone formation by cell-seeded calcium phosphate scaffolds as compared to the autograft, allograft and cell-seeded allograft implants. An extensive resorption of the autograft, allograft and cell-seeded allograft implants was observed by histology and confirmed by histomorphometry. Cell-seeded TCP implants also showed distinct signs of degradation with histomorphometry and μCT, while the degradation of the cell-seeded BCP implants was negligible. These results indicate that cell-seeded calcium phosphate scaffolds are superior to autograft, allograft or cell-seeded allograft in terms of bone formation at ectopic implantation sites. In addition, the usefulness of μCT for the efficient and non-destructive analysis of mineralised bone and calcium phosphate scaffold was demonstrated.
Seeding Osteoblasts onto Osteocytes: An In Vitro 3D Study
Judith Green,X. Edward Guo
Columbia Undergraduate Science Journal , 2006,
Abstract: Understanding the mechanisms by which bone cells communicate is vital in exploring diseases characterized by bone degeneration, namely, osteoporosis. Cell seeding has been used in two dimensional (2D) cell cultures to study how bone cells interact with one another, specifically, to prove the existence of gap junctions between osteocytes and osteoblasts. However, the natural three dimensional (3D) state of bone tissue requires examining it in 3D. Accordingly, the cell seeding procedure was tested on trabecular bone core explants to ascertain whether it is useful in 3D studies as well. When the dye concentrations taken from past 2D experiments were used, Day 1 showed many osteoblasts, but by Day 2 the cells were not visible. The dye concentrations were then doubled to determine if the osteoblasts were still seeded onto the bone cores and viable but not visible, or if they had actually died. With these dye concentrations, the stained osteoblasts were still visible on the second day after seeding, indicating that the cells were seeded and living. According to these results, it is evident that with minor modifications of the 2D procedure, it is possible to seed osteoblasts onto osteocytes in 3D, making this a credible test for the presence of gap junctions in 3D bone tissue.
Regulation of Bone Marrow Angiogenesis by Osteoblasts during Bone Development and Homeostasis  [PDF]
Ernestina Schipani,Amato J. Giaccia
Frontiers in Endocrinology , 2013, DOI: 10.3389/fendo.2013.00085
Abstract: Bone marrow is a highly heterogeneous and vascularized tissue. The various cell types populating the bone marrow extensively communicate with each other, and cell-to-cell cross talk is likely to be essential for proper bone development and homeostasis. In particular, the existence of osteogenesis and angiogenesis coupling has been recently proposed. Despite its high degree of vascularization, a gradient of oxygenation is present in the bone marrow, and the endosteal surface of cortical bone appears to be among the most hypoxic areas in the body. Oxygen (O2) is both an essential metabolic substrate and a regulatory signal that is in charge of a specific genetic program. An important component of this program is the family of transcription factors known as hypoxia-inducible factors (HIFs). In this Perspective, we will summarize our current knowledge about the role of the HIF signaling pathway in controlling bone development and homeostasis, and especially in regulating the crosstalk between osteoblasts, progenitor cells, and bone marrow blood vessels.
Page 1 /100
Display every page Item


Home
Copyright © 2008-2017 Open Access Library. All rights reserved.